Abstract
Patients with congenitally missing maxillary lateral incisor generally have issues with esthetics and pronunciation. This case will demonstrate how to determine bonding position and torque selection when we decide to substitute the congenital missing laterals with canines and first premolars with the canines, and reshape the canines to enhance anterior esthetics after space closure.
Bonding position: the primary reference point is the gingival margin. The ideal gingival height from central incisor, lateral incisor, and canine is ‘“High-Low-High”. For this purpose, we decide to bond the canine bracket more gingivally and the premolar bracket more occlusally for the future harmony of gingival height of anterior teeth.
2. Bracket torque selection: the primary concern is root prominence. In order to create an ideal root prominence for the canine and lateral incisor, we choose a high torque Damon Q canine bracket(+11°) for the canine to push the root into the alveolar bone and an original first premolar bracket(-11°) to increase the root prominence.
摘要
先天性缺失上顎側門牙常會對患者的美觀和發音帶來極大的影響，此案例為診斷後決定關閉缺牙空間，以犬齒取代側門齒、以第一小臼齒取代犬齒，待空間關閉後再進行型態修整以符合前牙美觀；以下介紹此類案例的黏著位置和矯正器角度考量。
1. 黏著位置：依照牙齦高度為參考點，目標是空間關閉後的前牙牙齦高度是“高-低-高“，因此犬齒的黏著位置要靠牙齦黏，使牙齦高度往咬合面移動，未來牙齦高度看起來像側門齒；同理第一小臼齒的黏著位置要靠切緣，使牙齦高度往根尖方向移動，未來牙齦高度看起來像犬齒。
2. 矯正器角度考量：依據為未來牙根豐隆度為考量，目標是使未來取代為側門齒的犬齒牙根豐隆度降低、而取代為犬齒的第一小臼齒牙根豐隆度提高；因此犬齒的矯正器考量應為高角度，以利將牙根壓入齒槽骨，而第一小臼齒則以原來的矯正器(-11°)即可增加牙根豐隆度。